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/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef API_FEC_CONTROLLER_H_
#define API_FEC_CONTROLLER_H_
#include <memory>
#include <vector>
#include "api/environment/environment.h"
#include "api/video/video_frame_type.h"
#include "modules/include/module_fec_types.h"
namespace webrtc {
// TODO(yinwa): work in progress. API in class FecController should not be
// used by other users until this comment is removed.
// Callback class used for telling the user about how to configure the FEC,
// and the rates sent the last second is returned to the VCM.
class VCMProtectionCallback {
public:
virtual int ProtectionRequest(const FecProtectionParams* delta_params,
const FecProtectionParams* key_params,
uint32_t* sent_video_rate_bps,
uint32_t* sent_nack_rate_bps,
uint32_t* sent_fec_rate_bps) = 0;
// 'retransmission_mode' is either a value of enum RetransmissionMode, or
// computed with bitwise operators on values of enum RetransmissionMode.
virtual void SetRetransmissionMode(int retransmission_mode) = 0;
protected:
virtual ~VCMProtectionCallback() {}
};
// FecController calculates how much of the allocated network
// capacity that can be used by an encoder and how much that
// is needed for redundant packets such as FEC and NACK. It uses an
// implementation of `VCMProtectionCallback` to set new FEC parameters and get
// the bitrate currently used for FEC and NACK.
// Usage:
// Setup by calling SetProtectionMethod and SetEncodingData.
// For each encoded image, call UpdateWithEncodedData.
// Each time the bandwidth estimate change, call UpdateFecRates. UpdateFecRates
// will return the bitrate that can be used by an encoder.
// A lock is used to protect internal states, so methods can be called on an
// arbitrary thread.
class FecController {
public:
virtual ~FecController() {}
virtual void SetProtectionCallback(
VCMProtectionCallback* protection_callback) = 0;
virtual void SetProtectionMethod(bool enable_fec, bool enable_nack) = 0;
// Informs loss protectoin logic of initial encoding state.
virtual void SetEncodingData(size_t width,
size_t height,
size_t num_temporal_layers,
size_t max_payload_size) = 0;
// Returns target rate for the encoder given the channel parameters.
// Inputs: estimated_bitrate_bps - the estimated network bitrate in bits/s.
// actual_framerate - encoder frame rate.
// fraction_lost - packet loss rate in % in the network.
// loss_mask_vector - packet loss mask since last time this method
// was called. round_trip_time_ms - round trip time in milliseconds.
virtual uint32_t UpdateFecRates(uint32_t estimated_bitrate_bps,
int actual_framerate,
uint8_t fraction_lost,
std::vector<bool> loss_mask_vector,
int64_t round_trip_time_ms) = 0;
// Informs of encoded output.
virtual void UpdateWithEncodedData(
size_t encoded_image_length,
VideoFrameType encoded_image_frametype) = 0;
// Returns whether this FEC Controller needs Loss Vector Mask as input.
virtual bool UseLossVectorMask() = 0;
};
class FecControllerFactoryInterface {
public:
virtual ~FecControllerFactoryInterface() = default;
virtual std::unique_ptr<FecController> CreateFecController(
const Environment& env) = 0;
};
} // namespace webrtc
#endif // API_FEC_CONTROLLER_H_